Rock drill



July Z5, 1933. G. H. FUEHRER ROCK DRILL 2 Sheets-Sheet l Filed Feb. 20. 1932 INVENToR.

eozjllfzehren EISA TTORVNEY.

. July 25, 1933. G. H. FUEHl-QER 1,919,717

ROCK DRILL Filed Feb. 20. 1932 2 Sheets-Sheet 2 INVEN TOR. Geol' cIlI/zezfe BY Z Z 1f HIS A TToRNEY Patented July 25, 1933 l UNITED STATES PATENT oFFlcE GEORGE H. FUEHRER, OF EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION 0F NEW JERSEY ROCK DRILL `uppnca'cion mea February 2o, 1932. serial No. 594,196.

This invention relates to rock drills, but more particularly to the pressure Huid distributing or valve mechanism of rock drills of the hammer type wherein the rotation mechanism acts through the piston for imparting rotary movement to the drill steel.

One object of the invention is to impart shocks or jars to the rotation mechanism for freeing the drill steel whenever it becomes stuck in the drill hole.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference characters refer to similar parts,

Figure l is a longitudinal view in section showing the valves in position for admitting pressure fluid into the rear end of the piston chamber to actuate the piston on its working stroke, and

Figure 2 is a View similar to Figure 1 showing the piston and the main ,distributing valve in other limiting positions.

Referring more particularly to the drawings, the rock drill, which is designated in general by A, comprises a cylinder B having a piston chamber C to accommodate a reclprocatory hammer piston D.

The piston D is of a well known typecom- V prising a head E and a forwardly extending nose or stem F which is guided by a front cylinder washer G disposed at the front end of the piston chamber C to form a closure therefor. serves to centralize a front head H with respect to the cylinder B and may, as shown, extend partly into both.

Within the front head H is a-rotatable f chuck J for guiding a working implement, such as a drill steel K, against which the blows of the hammer piston D are delivered. The drill steel K may, as is customary, be suitably 'interlocked with the chuck J to prevent relative rotary movement between these elements, and in the rear end of the chuck J are introverted ribs L to engage flutes O in the stem F of the piston.

The rock drill is provided with the usual rotation mechanism comprising a rifie bar P which extends into the piston D to interlock The front cylinder washer G alsoend of the piston chamber C, and on the rear end of the rotation ratchet R is a back head U which may be secured to the cylinder B in any suitable manner.

On the side of the cylinder B is a valve chest V having a bore which extends longitudinally therethrough to form a valve chamber 'W for the accommodation of a distributing valve X. The valve X is of the spool type and has a bore Y therethrough to receive a rod Z upon which the valve slides. The rod Z is provided at one end with a head b whichpreferably lies within an enlarged portion c of and at the front end of the valve chamber W. The rod extends with its opposite end through a plug d which forms a closure for the rear end of the Valve chamber W. The rod may be suitably threaded for the accommodation of a nut e which seats against the plug l to hold said plug and the rod Z fixedly in the valve chest The intermediate portion of the valve X is in the form of a stem f around which pressure fluid flows to the ends of the piston chamber C, and communication between the intermediate portion of the valve chamber W and the ends of the piston chamber is controlled by flanges g and h arranged at the front and rear ends respectively of the stem The flange g controls an inlet passage j which `affords communication between the valve chamber and the front end of the piston chamber C, and the fiange L controls an inlet passage 7c throughwhich pressure fluid flows from the valve chamber to the rear end of the piston chamber C.

The inlet passages j and c serve the additional function of conveying exhaust 'fluid from the ends of the piston chamber and the exhaust of the fluid from the piston chamber is, in the present instance, also controlled by the valve X. The valve X is acsage j and an exhaust port r in the valve' der anda groove w in cordingly provided with a pair of annular external grooves 0 and p located forwardly of the flange g and rearwardly of the flange L respectively. The groove p serves to establish communication between the inlet passage 7c and an atmospheric exhaust port g in the valve chest V, and the groove o affords communication between the front inlet paschest and which is located forwardly of the inlet passage y'.

Located forwardly of the groove o is a flange s having an annular actuating surface t against which pressure fluid may act to actuate the valve X rearwardly. The pressure fluid utilized for this purpose is valved, to a pressure chamber u wherein the actuating surface t lies, by the piston D, and suchl pressure fluid vis conveyed to the pressure chamber u by a kicker passage o in the cylinthe periphery-of the flange s.

The kicker passage lv opens into the piston chamber C at a point rearwardly of the inlet passage y' and with its outlet end v into the valve chamber W. The outlet end m and the groove w are so proportioned that thefsaid outlet end may be in communication withV the groove. The groove lw is, moreover, of such width that in the forward limiting position of the valve X said groove w will establish communication between tho outlet opening o: of the kicker passage v and the pressure chamber u. Preferably, the pressure chamber u is provided with a small atmos heric vent y to provide an immediate escape or the pressure fluid admitted into the pressure chamber ufor kicking the valve.

The rear bounding surface of the groove p is provided by a flange z which has an annular external groove 2 for establishing communication between the kicker passage 3 in the cylinder B and a pressure chamber 4 near the rear end of the valve chamber W. The groove 2 is of suitable extent to admit pressure fluid from the kicker passage 3 into the pressure chamber 4 and wherein it may act against an annular actuating surface 5 on the rear end of the flange a for actuating the' valve, X forwardly. v

The kicker passage 3 communicates with the piston chamber C at a point forwardly of the inlet passage c, and the outlet opening 6 of the kicker passage 3, and which opens into the valve chamber W, is so located that it will at all times be in communication with the groove 2 in the flange z. The pressure chamber 4 is provided with an atmospheric vent 7 which serves the same functionv as the atmospheric vent .g/ leading from the pressure chamber u.

The admission of pressure fluid into the valve chamber W is controlled by a throttle valve 8 arranged in a chamber 9 in the valve chest V. The throttle valve 8 is preferably bore 10 into the intermediate portion of the valve chamber W.

The operation of the device so far described is as follows: With the piston and the valve in the rearmost positions in their respective chambers pressure fluid will flow from the intermediate portion of the valve chamber through the inlet passage lc into the rear end of the piston chamber C and will drive the piston D forwardly against the drill steel K. During this forward movement of the piston D the rifle bar will rotate a partial revolution, in a well understood manner, and during the forward movement of the piston the air in the front end of the piston chamber C will be expelled through the inlet passage y', the annular groove o and the exhaust port 1', so that the forward blow of the hammer piston will be unimpeded by compression.

. As the piston D advances in a forwardly direction it uncovers the kicker passage 3. Pressure fluid then flows through the kicker passage and the annular groove 2 and into the pressure chamber 4. There it will act against the actuating surface 5 and shift the valve X forwardly. This movement of the valve will take place at or about the time the piston D strikes the drill steel K.

In the new position of the valve the annular groove p affords communication between the inlet passagel lc and the exhaust port g, thus providing an outlet for the pressure fluid employed for driving thepiston D forwardly. The flange g of the valve then uncovers the v.front inlet passage j. Pressure fluid thereforel flows from the valve chamber through the inlet passage j into the front end' of the piston chamber C and drives the piston D rearwardly.

During this movement of the piston it will describe a partial revolution, since then the rifle bar P will be held stationary by the pawls S ,which engage the rotation ratchet R. Being interlocked with the chuck J the piston will cause the said chuck and, therefore, the drill steel to describe a similar rotary movement preparatory to the vsucceeding forward stroke of thepiston D.

After the piston D has moved rearwardly throughout a portion of its stroke it uncovers the kicker passage v. Pressure fluid then flows through said kicker passage and the 'groove -w and into the pressure chamber u where it acts against the actuating surface t and returns the valve X to its initial position. This cycle of Ioperations may continue indefinitely or as long as the piston D is unhampereg in its movement in the piston chamber As is well known, in drills of the character described and wherein the piston acts as a component part of the rotary mechanism anything which impedes the rotary movement of the drill steel also retards the action of the piston. In a case. Where the detritus in the drill hole accumulates about the drill steel to such an extent as to completely arrest rotation of the drill steel the piston D will, in consequence, be held immovable in the piston chamber. This is due to the fact that, as previously explained, the piston is interlocked with both the chuck whereby the drill steel is guided and with the rifle bar P.

Generally, When the drill steel becomes stuck in the drill hole it is an exceedingly difficult matter to free it from the rock face. It

.is accordingly contemplated to equip the drill with means whereby, when the piston and vthe valve become inoperativedue to the stickthe valve chest 12 is a valve chamber 13 to front end of the main valve chamber W. 'In

the arrangement shown the valve chest 12 is seated upon the plug 15, and the head b of valve chest 12 and serves to clamp the valve chest 12 and the plug 15 fixedly in their assembled positions.

As may be readily ascertained by reference to the aforesaid patent, the valve 14 is adapted to rock on its transverse median line to seat intermittently with its Wings 17 and 18 upon 1the seating surface 16. The wing 17 controls an inlet passage 19 which extends through the plug 15 and the rod Z into a pressure chamber 20 in the plug d. The pressure chamber 20, in the present instance, serves as a guide for a reduced extension 21 .on the valve X and the rear end of which extension constitutes an actuating surface 22 against Which the pressure fluid admitted into the pressure chamber 2O may act for actuating the valve.

Preferably the pressure chamber 20 is provided with an atmospheric vent 23 through which a portion of pressure fluid may escape to the atmosphere immediately upon the admission of pressure fluid into the pressure chamber 20. The pressure chamber 20 is,

reduced extension 28 on the valve X. At the front end of the pressure chamber 26 is an atmospheric vent 29 which serves the same function as the vent 23 but is preferably of smaller area than the vent 23 so that in the event that pressure fluid of the same value is admitted into both pressure chambers 26 and 20, that in one, as for instance in the pressure chamber 26 will be of a sufficiently higher value to assure movement of the valve X to a limiting position. The pressure chamber 20 is also provided with a main exhaust port 30 controlled by the. front end of the extension 28 and through which the main charge of pressure fluid may escape from the pressure chamber 26 to the atmosphere.

The pressure fluid intended to be distributed by the valve 14 is conveyed into the valve chamber 13 by a supply passage 31 which communicates with the valve chamber 13 through a port 32 in the valve chest 12. The opposite end of the passage 31 opens into the valve chamber 9 and is therefore communicable with 'the port 11 in the throttle valve 8, said port 11 being of such extent as to register with both the passages 31 and the valve chamber W in one position of the throt- Jtle valve 8. the rod Z in turn seats upon the end of the During the'normal operation of the drill or, in ot er words, during the time that the valve X reciprocates freely and is controlled by the piston for distributing the pressure fluid to the piston chamber, the throttle valve 8 occupies a position w-herein the port 11 registers only with the valve chamber W. When thus operating it is desirable that the valve subjected to an unnecessary battering which it would receive as a result of the vibration to which the entire drilling mechanism is subjected. The means provided for thus holding the valve 14 fixedly in the valve chamber 13 comprises a sleeve 33 which is disposed in the valve chamber 13 and has at its rear or inner end an introverted flange 34 which engages the periphery of the rod Z to assist in guiding the sleeve 33.

At the front or outer end of the sleeve 33 is a lateral lian e 35, the inner end surface of which constutes a pressure area 36 against which pressure fluid in the valve chamber 13 acts to press the flange 35 against the head b. The outer or front surface of 14 be held immovable so that it will not be the flange 35 is provided with a. Vrecess 37 which is in communication with atmospheric vents 38 in the head b to provide an escape for an pressure fluid which may leak from the va ve chamber 13 along the cooperating surfaces of the flange 34 and the rod Z.

Disposed within the sleeve 33 is a s ring 39 which acts with one end against the ange 34 and seats with its other end against the head b.

The operation of' the valve li and associated elements is as follows: lVhenevcr the working implement or drill steel K becomes stuck in the drill hole, and in consequence of which the movement of the hammer piston D is arrested so that the valve X will also cease to reciprocate, the throttle valve S may be rotated to the position illustrated in the drawings wherein the port 11 registers with both the valve chamber W and the supply passage 31. In this way pressure fluid will be admitted into the valve chamber 13. Such pressure fluid will act against the pressure area 36 of the sleeve 3:5 and will move said sleeve against the head b a slight distance to release the valve l-l, it being linderstood, of course, that the valve 14 will, in the absence of pressure fluid in the valve chamber 13, be held against vibratory movement by the spring 39.

After the valve l-l is free to move it will osciilatc to distribute pressure fluid to thc pressure chambers 2G and 20. In the position ofthe valve 14 illustrated pressure fluid flows over the wing 17 and through the inlet passage 19 into the pressure chamber 20. The pressure fluid thus admitted into the pressure chamber drives the valve X forwardly to communicate the front end of the piston chamber' C with the valve chamber IV, tlms subjecting the forward face of the piston head E to a charge of pressure fluid.

As the valve X moves forwardly the eX- tension 21 uncovers the exhaust port 24 and the pressure fluid will then escape from the chamber 2l) to the atmosphere. This will permit the valve 1l to oscillate to its other extreme position wherein pressure fluid flows over the wing 18 through the inlet passage 25 into the pressure chamber 26. Such pressure fluid acting against the actuating surface 2T then moves the valve X rearwardly to establish connnunication between the intermediate portion of the valve chamber lV and the rear end of the piston chamber (l.

The rear face of' the head E of the piston will thus be subjected to a charge of pressure fluid acting in a forwardly direction. and upon each movement of the valve X to an extreme position pressure fluid will be exhausted from one end or the other of the piston chamber as duringr the normal operation of the drill.

These movements of the valves 14 and X may continue for subjecting the end surface of the head E of the piston D to intermittently applied charges ofl pressure fluid. Although the drill steel mayy at first resist the jars applied to the rotation mechanism by the piston, in practice it has been found that the movement of the piston D in the piston chamber C will gradually increase and that the drill steel will, within a brief period of' time', be jarred loose in the drill hole so that the piston D will again be free to complete its full nominal stroke.

After the undersirable conditions in the drill hole have been overcome the throttle valve 8 may again be rotated to supply pressure fluid only to the valve chamber lV and the spring 39 will then press the sleeve 33 against thevalve 14 to hold said valve immovable upon the seating surface 16.

l claim:

1. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, a distributing valve for effecting the distribution ol' pressure fluid to the piston chamber and being normally actuated by pressure fluid valved by the piston, a second valve for controlling the flow of pressure fluid to the distributing valve for actuating said distributinar valve, and means for selectively supplyinft pressure fluid to the Valves.

2.. In a fluid actuated rock drill, the conibination of a cylinder having a piston chainbe and a piston in the piston chamber, a distributing valve for distributing pressure fluid to the ends of the piston chamber` opposed actuating surfaces on the valve intel'- mittently exposed to pressure fluid valved by the piston for ynormally actuating the valve, other opposed actuatingr surfaces on the valve, a second valve for admitting pressure fluid to the second said actuating surfaces to aetuate the distributing valve. and means for selectively supplying pressure fluid to the valves.

3. In a fluid actuated rock drill, the coinbination of a 'cylinder having a piston chamber and a piston in the piston chamber, a' valve chest having a Valve chamber, a distributing valve in the valve chamber for distributingr pressure fluid to the piston chamber, a pair of opposed actuating surfaces on the valve intermittently exposed to pressure fluid valved by the piston `for normally actuating the valve, a second pair of opposed actuating surfaces on the valve and being! of larger area than the first said actuatin .'P surfaces. a second valve adapted to be selectivelv set in operation for distributing pressure fluid to the second mentioned actuating surfaces., and cont-rol means for selectively supplying pressure fluid to the Valves.

4. In a fluid actuated rock drill, the combination of a cylinder having-a piston cham- ,ber and a piston in the piston chamber, a

valve chest having a valve chamber, a dissurfaces,

tributing valve in the valve chamber for distributing pressure fluid to the piston chamber, a pair ofopposed actuating surfaces on the valve intermlt-tently exposed to ressure Huid valved by the piston for normaily actuating the valve, a second pair of opposed actilatin'g surfaces on the valve and being of larger area than the first said actuating surfaces, a second valve adapted to be selectively set in operation for distributing pressure flul to the second mentioned actuating surfaces, spring pressed means for holding the second mentioned valve in fixed position during the normal operation of the rock drill, and fihrottle valve for selecti rely supplying pressure fluid to the Valras.

5. I; a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, a valve chest having a valve chamber, a distributing valve in the valve chamber for distributing pressure fluid to the piston chamber, a pair of opposed actuating surfaces on the valve intermittently exposed to pressure fiuid valved by the piston for normally actuating the valve, a second pair of opposed actuating surfaces on the valve and being of larger area than the first said actuating surfaces, a second valve adapted to be selectively set in operation for distributing pressure fluid to the second mentioned actuating spring pressed means for holding the second mentioned valve in fixed position during the normal operation of the rock drill, a pressure area on the spring pressed means selectively exposed to pressure Huid to actuate said means into position for releasing the second mentioned valve, and a throttle valve to selectively supply pressure fluid to the valves and to the pressure area.

6. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber'and a piston in the piston chamber, a valve chest having a valve chamber, a distributing valve. in the valve chamber for distributing pressure uid to the piston chamber, a pair of opposed actuating surfaces `on the valve intermittently exposed to pressure fluid valved by the piston for normally actuating the valve, a second pair of opposed actuating surfaces on the valve and being of larger area than the first said actuating surfaces, a second valve for selectivebination of a cylinder having a piston chaml ber and a piston in the piston chamber, a distributing valve for effecting the distribution of pressure fluid to the piston chamber and being normally actuated lr; pressure fiuid issuing from the cyiinder, a second valve to selectively control the How of pressure fiuid to the distributing valve for actuating said distributing valve, and means for selectively supplying pressure fluid to the valves.

- 8. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, a distributing valve for effectin the distribution of pressure fluid to the plston chamber and having a. plurality of palrs of actuating surfaces of which one pair is normally subjected to pressure fluid issuing from the cylinder, a second valve to selectively control the flow of pressure fluid to another pair of actuating surfaces, means for selectively supplying pressure fluid to the valves, and means for holding the second mentioned valve immovable during thev normal operation of the rock drill.

9. In a fiuid actuated rock drill, the combination of a cylinder having'a piston chamber and a piston in the piston chamber, a distributing valve for effecting the distribution of pressure fiuid to the piston chamber and having a pair of opposed actuating surfaces normally subjected to pressure fiuld issuing from the cylinder, a second pair of opposed actuating surfaces on the valve, a second .valve to selectively control the flow of pressure fiuid to the last mentioned actuating surfaces, locking means for holding the second mentioned valve immovable during the normal operation of the drill and having a ressure area, a spring for holding the loc ing means in one limiting position, and a throttle valve for selectively supplying pressure fiuid to the valves and to the pressure area for holding the locking means in another limiting position.

GEORGE H. isUnHRER.` 

